Women's shoes often have high heels or spike heels of various heights and thicknesses. It is estimated that as many as 59% of all women in the United States wear them regularly because they consider them preferable and more fashionable than flats or shoes with lower heels. However, a recent Gallop survey also shows that among these high-heel shoe wearers, 62% have foot pain, blisters, bunions, corns, calluses or other foot problems. Undoubtedly, as a result, the same survey shows that slightly more than half of those women wear high-heel shoes less often than they did five years ago. We believe that these foot problems are, to a large extent, due to the excessive omnidirectional shock forces that are routinely transmitted through the ball and heel portions of the wearer's feet into the spine when she walks wearing a pair of these shoes.
More particularly, when one walks barefoot or in flats, the heel and ball of the foot are more or less in the same plane. With each stride, the heel strikes the floor first followed by the ball of the foot and then the toes in a progressive rolling motion. Also, there is relatively large-area contact between the foot and the floor at any given time and little possibility to twist an ankle because the heel bone serves effectively as the unidirectional "heel". As a result, there is a smaller impulse and shock force imparted to the foot each time the foot strikes the floor. A typical high heel shoe, on the other hand, has a heel that is 2-3 inches long. This means that the heel portion of the wear's foot is supported 2-3 inches above the ball and toe portions of the foot that rest on the sole of the shoe. Accordingly, when a woman walks in a pair of high heels, although the heel of each shoe strikes the floor first, there is no progressive rolling motion of the foot as described above. Rather, the foot approaches the floor more vertically, with the heel and sole of the shoe striking the floor almost simultaneously. There is very little redirecting and dissipating of those impact forces as occurs when one wears low heel shoes or flats. At most, the heel may have a lift on top on its lower end that is somewhat resilient, but this lift frequently becomes worn away after a relatively short period of time. Resultantly, each time the wearer steps out, a very strong impulse is transmitted without any directional control via the heel and ball portions of the wearer's foot directly to her ankle and leg sending shock forces in any direction through the shoe structure, thus making foot injuries possible.
Also, it is a fact that most high heel shoes, particularly the more fashionable ones, have heels whose ends are quite narrow, i.e. of small area. Consequently, all of the reaction forces developed as a result of the wearer's weight and momentum while walking are concentrated primarily in the narrow heel area of the shoe.
Furthermore, the fixed incline of the shoe at the arch required to position the heel and ball portions of the wearer's foot at such different elevations mandates that the area of the shoe sole underlying the ball portion also have a relatively small area. Therefore, the shock forces produced by each footfall are concentrated also on that part of the wearer's foot and propagated from there into the spine where the shock energy is dissipated in the spinal discs. This stress on the ball of the foot is exacerbated because as soon as the sole of the shoe strikes the floor, the wearer's foot tends to slide down the inclined arch of the shoe so that the ball of the foot impacts the bottom of the shoe, while the toes are jammed against the toe and vamp of the shoe. All of these dynamic effects undoubtedly contribute to the spinal problems and foot problems mentioned at the outset, as well as to ankle pain and leg fatigue suffered by many women who have to walk long distances during the course of their day.
Also, of course, the forces concentrated in the heel area of a woman's high heel shoe worn while walking also causes great stress on the heel itself, particularly at the narrow end thereof. Sometimes the heel becomes bent or deformed; in extreme cases, the end of the heel actually breaks off.
Men's shoes, in contrast, are not as painful to wear as women's high-heeled shoes, but men's shoes with hard heels impart the same shock forces into the spine and the foot bone structure so as to cause similar medical problems for men.